April 24 – Look! Up In The Sky!

Today’s Factismal: The Hubble Space Telescope has made over 1,000,000 observations in the 25 years it has been in orbit.

It is rare to have a failure turn into a success. And it is even rarer to have that success become a beloved part of the scientific community. And yet, that is exactly what happened with the Hubble Space Telescope, or HST for short.

The Hubble Space Telescope in orbit (Image courtesy NASA)

The Hubble Space Telescope in orbit
(Image courtesy NASA)

The HST wasn’t the first telescope in space (that honor belongs to an unnamed telescope flown on a sounding rocket), nor was it the first telescope into orbit (that would be the Explorer 11 satellite, launched in 1962). What it was was the first orbiting space telescope that had a large enough mirror to do a better job than ground-based telescopes and that could be upgraded. Another thing that it was, though this wasn’t widely known at the time, was a prototype for a new series of spy satellites.

An image of galaxies in a small portion of the dark sky. IThe HSAT stared at one spot for nearly five days to make this image. (Image courtesy NASA)

An image of galaxies in a small portion of the dark sky. The HST stared at one spot for nearly five days to make this image.
(Image courtesy NASA)

Astronomers wanted a telescope in space because it would allow them to overcome the jitter and optical distortion caused by the Earth’s atmosphere and because it would allow them to do things that literally cannot be done on Earth, such as looking in one spot for a five days at a time. And NASA wanted to give them one. So together and with a little help from the NRO, they convinced Congress to fund the HST – though Congress denied NASA the funds to test the mirrors (a decision that they would regret).

Even with funding, it took time to build the HST. And by the time that the HST was ready to launch, the Space Shuttle had suffered a major setback and was on hold. What with one thing and another, the telescope that had been proposed in 1974, built in 1979, and ready for launch in 1986, didn’t actually make it into orbit until 1990, some sixteen years after the program began.

An early image from teh HST showing hte

An early image from the HST showing the “astigmatism” problem
(Image courtesy NASA)

But the worst was yet to come. Though the HST was producing good images, they weren’t great. A check of the calibration equipment showed that the mirror had been mis-ground, introducing a type of astigmatism that kept it from giving the best images it could. Instead of showing up as sharp points, the stars were blurry disks. America’s great space telescope was a flop and NASA was the laughing stock of the world.

So NASA sent another mission to the telescope, a mere three years after it had been launched. The astronauts fitted the Hubble with a corrective lens that removed the astigmatism. And the images started flowing out. Hubble brought us close-ups of new stars being born and of the wonders hidden in the “dark” sky. Over the next fifteen years, Hubble met every mission objective and then some.

A barred galaxy as seen by the HST (Image courtesy NASA)

A barred galaxy as seen by the HST
(Image courtesy NASA)

But the world of Earth-bound astronomy had forged ahead in the meantime. We now had telescopes with adaptive optics that could do almost everything that the HST could only with larger mirrors and lower costs. By 2009, the HST had become obsolete and NASA planned to scrap it. However, a letter-writing campaign showed that there was enough public support for one last mission to upgrade the HST and keep it flying for another five years. And so NASA made one last set of adjustments to the turkey that became a star.

Today, the HST is orbiting somewhere overhead, taking pictures of the cosmos and sending them down for us to see, enjoy, and use. If you’d like to help in that last part, then why not join the astronomers at Galaxy Zoo as they classify galaxies using images from the HST?

April 22 – Down To Earth

Today’s Factismal: The 45th annual Earth Day celebration is being held today.

The 1960s and 1970s were a difficult time for the environment. The Cuyahoga river had caught fire in 1969 (and not for the first time). Overuse of pesticides had led to bald eagles, whooping cranes, and many other species of bird becoming endangered. Dumping of toxic wastes into the oceans and bays had led to widespread poisoning in places such as Minimata and had taken Maine lobsters off of the market. And hidden dumps of toxic waste in places such as Love Canal had created a seemingly endless parade of cancer-ridden children.

By 1969, the epidemic of environmental crises had become nightly news. But where most were to content to curse the oncoming dark, two men wanted to light a candle. The first was UNESCO worker John McConnell, who proposed that the United Nations designate the equinox (March 21, 1970) as a day of environmental awareness and celebration of the Earth; he proposed calling it “Earth Day”. The second was Wisconsin Senator Gaylord Nelson who urged teachers and environmental activists to take part in a “teach-in” on April 22, 1970. His idea took root and blossomed into an event that included more than 20,000,000 people; nearly 10% of the US population participated.

The poster for the very first Earth Day (Image courtesy Walt Pogo)

The poster for the very first Earth Day
(Image courtesy Walt Kelly)

The next year, the two celebrations were merged. The name of the first and the date of the second came together to give us the Earth Day celebration that has become a global tradition. Every year, scientists, students, and ordinary citizens come together to celebrate what we’ve learned and to work to protect the Earth.

Thanks in part to Earth Day, the environment has become much cleaner over the past four decades. Federal agencies such as the EPA (established in response to tragedies like Love Canal and the Cuyahoga fire) have reduced pollution and enforced common standards that have made life better and longer for everyone. Bald eagles,which at one time were reduced to a mere 412 nesting pairs, now number in the tens of thousands. Toxic waste sites like Love Canal have been cleaned up. And the pernicious smog of Los Angeles is now a rare annoyance instead of a daily threat.

If you’d like to take part in Earth Day this year, then head on over to:

April 18 – Soda Pops!

The only thing better than science is science that ends up making a huge mess. In today’s installment of the Secret Science Society, Mary, Daniel, and Peter discover exactly why candy plus soda pop makes such a big mess in Soda Pops!


As was normal for a Saturday morning, the Secret Science Society was in the backyard, making a mess. And the mess was everything that they had hoped it would be. Taking turns, Mary, Peter, and their friend Daniel would each open up a bottle of soda and then drop several small candies into it and quickly jump back to avoid the geyser of foam spewing out of the bottle.

“This is great!” Peter enthused. “I wish we had more soda!”

“That would be fun, but I wish we knew why it worked,” Daniel said.

“Me, too,” Mary replied. “Why does adding candy to soda make it spurt out like that? A scientist would know how to figure it out!”

At that moment, a voice from behind them called out “Then it is a good thing that you are all scientists, isn’t it?”

“Hi, Mom!” Peter said. “Taking a break from the cosmos?”

“Yes; I’ve found enough new planets for this week.” Peter’s mother studied planets around other stars and did most of her work at home. “I decided to come out and see what all the squealing was about.”

“We’ve been making soda fountains,” Mary said. “But we can’t figure out why it happens.”

“Well, let’s think about this,” Peter’s mother replied. “What goes into the reaction?”

“Carbonated soda and candy,” Daniel said.

“And we get foam and a lot of carbon dioxide out,” Peter added.

“OK, so we have to decide what it is about the candy that makes the carbon dioxide come out so quickly. What is the candy made up of?”

“It is mostly sugar with some mint flavor,” Mary said.

“And is the candy smooth or is it rough?”

Daniel peered closely at one of the candies in his hand. “It is sort of rough on the outside; there are lots of little bumps and holes on it.”

“Then we’ve got three possibilities,” Peter’s mother said. “First, it could be that the mint oil makes the reaction happen. Second, it could be that the sugar makes it happen. Third, it could be that the candy’s rough outside makes it happen. How can we find out the answer?”

“We could put a little oil into a bottle of soda,” Peter said. “If it makes the soda fountain out, then we’ve found the answer.”

“And we could try adding sugar to soda,” Daniel added. “If it makes the soda fountain out, then we’ve found the answer.”

“And we could add something that isn’t sugar but looks like it to the soda,” Mary concluded. “If the soda boils out then we know that it isn’t sugar that makes it go. But what has rough edges like sugar?”

“Salt does,” Peter said. “Let’s try it and see what makes the soda go!”

Eagerly, the three ran into the kitchen to gather up the supplies that they’d need. Daniel grabbed a bowl of sugar. Mary picked up a salt shaker. And Peter rummaged in the pantry until he found the oil. The friends then went back outside to run their experiment.

What do you think will happen? Do the experiment!




“Me first!” Peter said. He grabbed a soda bottle and took off its cap before setting it back on the ground. He carefully poured a little oil into the bottle and moved back.

“Nothing’s happening!” Daniel said. “It must not be the oil in the candy. Let’s try the sugar.” He opened a second bottle of soda and set it on the ground. He poured in some sugar and jumped back to avoid the rush of foam. “Aha! It’s the sugar!”

“Don’t jump to conclusions,” Mary said. “Let’s see what happens with the salt.” Mary took her turn opening a bottle of soda and then added salt to it. Again the soda fountained out of the bottle.

“So it isn’t sugar that makes it work,” Peter said. “I guess we should have known that because soda with sugar doesn’t spray out of the bottle.”

“Not unless you shake it up,” his mother agreed. “What happened is that both salt and sugar have a lot of rough edges; you can see them in a magnifying glass if you look. Those edges give the carbon dioxide a place to come out of solution.”

“Neat!” Mary said. “So anything with rough edges will make it work?”

“That’s right,” Peter’s mother replied. “If you look carefully at a glass with soda in it, you will see that there is often a stream of bubbles coming from a place on the glass. That’s where the glass has a small crack or a bit of something stuck on it. Scientists call those nucleation points. The more nucleation points there are, the more gas that can come out of solution.”

“But why do the bubbles come out at the edges?” Daniel asked.

“The exact reasons aren’t known yet,” she replied. “We know that part of the reason is because water molecules like to stick together; we call that surface tension. At a nucleation point, the water sticks to itself and not the glass or sugar or whatever. But the gas doesn’t stick together, and fills the gap. That pushes the water back a little, which lets more gas into the area. The reaction feeds on itself and you get a bubble that is too big to stay in place so it floats up and a new one starts. Do it fast enough by having lots of nucleation points and you get…”

“A soda fountain!” Mary exclaimed.

“OK,” Daniel said. “That makes sense. But why does diet soda work better?”

“That’s because of another effect,” Peter’s mother explained. “The sweetener in diet soda makes the water molecules stickier so that they make strong bubbles. That lets the foam hold together, which makes it go higher. But you could do the same thing by adding some glycerine and soap to a regular soda.”

“Yuck! I sure wouldn’t want to drink that!” Mary exclaimed.

“Me neither!” Peter’s mother replied. “But I would like to have some fun.”

Grabbing the candy, she turned to the soda to make her own fountain.

April 17 – “To The Moon, Alice!”

Today’s factismal: The New Horizons probe to Pluto carries a telescope named Ralph and a spectrometer named Alice.

If you grew up in the 1950s or are a fan of the Flintstones, then you probably know all about the eternally loving, perpetually squabbling couple at the center of both stories: Ralph Kramden and his wife Alice. And if you aren’t about all you need to know to understand the New Horizon probes instrument names is that whenever he would get particularly upset, Ralph would hyperbolically threaten his wife by saying “One of these days! Bang! Pow! To the Moon, Alice!”

The New Horizons probe is on a hyperbolic path (Image courtesy NASA)

The New Horizons probe is on a hyperbolic path
(Image courtesy NASA)

And that threat is actually a pretty close description of the New Horizons mission. With a mighty bang, it lifted off from Cape Canaveral on January 19, 2006. Whizzing through empty space at 37,000 mph, it was the fastest spacecraft at launch ever. How fast was it? It was going so quickly that it was guaranteed never to return to the inner Solar System; indeed, it would escape the Sun altogether on what is known as a hyperbolic trajectory. But even that wasn’t fast enough to get the probe to Pluto in a reasonable amount of time (ten years is reasonable, yes?) So the probe’s path was planned to take it past Jupiter where the probe added more velocity to end up moving at an amazing 51,000 mph! To put this into perspective, it would take something moving at that velocity about five hours to cover the distance between the Earth and the Moon.

The New Horizons spacecraft will meet Pluto in two months(Image courtesy NASA)

The New Horizons spacecraft will meet Pluto in two months
(Image courtesy NASA)

And now the probe is finally getting close enough to Pluto to start testing out its instruments, including Ralph and Alice. Ralph will be the workhorse of the probe for the next few months; it is a telescope containing a near-infrared imaging spectrometer (to help understand Pluto’s surface composition) and a a visible-light CCD imager (to take lots of pretty pictures). But Alice won’t be sitting idly by; she’ll use her ultraviolet imaging spectrometer to gather information for scientist studying Pluto’s atmosphere. Unlike Ralph, this won’t be the first “Alice” in space; another one flew on the ESA’s Rosetta mission.

The first color image by Ralph, the probe's camera system (Image courtesy NASA)

The first color image by Ralph, the probe’s camera system
(Image courtesy NASA)

Now the image of Pluto isn’t cool just because it is an image of Pluto (though that is pretty cool). It is also the best image that we’ve ever had of Pluto’s surface. And though it is pretty blurry, the viewing and the pictures will rapidly get much better right up to the point when New Horizons whizzes by Pluto on July 14. And that’s where the citizen science comes in. Because the data will be coming in hot and heavy during the few days when the probe is close enough to get a good view of the planet and its moons, the scientists are lining up the names for those things now – and they want your help! They have set up a web form for us to vote on various names for Pluto’s features and to propose names of our own. Of course, even if a name is popular, that’s no guarantee that it will be used; the IAU (the folks who don’t know what a planet is) overruled the name picked by the discoverer of Pluto’s fifth Moon (Vulcan) for one of their own (Kerberos). But it will still be fun to name the features and learn more about this amazing planet as New Horizons makes a fifty-year old dream come true in three months. For more information, zoom on over to:

April 15 – Nothing But The Tooth

Today’s factismal: Children have fewer teeth than adults (in humans, at least).

The human tooth is an amazing thing. Made up of a meaty pulp filled with blood vessels and nerves, it is covered by a thick layer of collagen mixed with minerals known as dentin which is covered by either enamel (on the part that sticks into the mouth) or cementum (on the part that sticks into the jaw). Strong enough to last for sixty years or more (with lots of brushing and very few candy bars), human teeth are surprisingly brittle and can chip or break when the tooth meets an unexpected bit of bone or stone in your food. And, unlike bones, a broken tooth won’t heal; instead if will just sit there with its nerves exposed for all the world to poke.

We have teeth specialized for grinding grains (molars, from the Latin for “millstone”) and for cutting meat (incisors, from the Latin for “cutting”) and for pretending to be a vampire (canines, from the Latin for “sparkly”).  And amazingly, we have different numbers of teeth as we get older. Babies have no teeth (for which their mothers are eternally grateful). But that soon changes; by the age of six, the babies start teething and the parents stop sleeping. These temporary chompers are variously known as “baby teeth” or “milk teeth” or deciduous teeth (because they fall out like the leaves of deciduous trees). And, because children have smaller jaws than adults, there are only twenty deciduous teeth in the typical human where there will be thirty-two adult teeth. Of course, there are exceptions to this rule, such as the case of poor Ashik Gavai who suffered from a rare form of cancer that caused him to grow 232 teeth on one side of his mouth!

The fact that children have a different number of teeth than adults is often used by forensic scientists to help identify bodies. By looking at the number and wear on teeth, they can estimate the age of a person. Or at least, they think they can. What they’d really like to do is to know that they can. And that’s where you come in!

Over at the Dental Arcade Game, a forensic pathologist is asking for people under the age off 25 to tell them about their teeth. How many deciduous teeth do you have? How many permanent teeth? When did they show up? By learning this information and linking it to other factors such as ethnicity and income, they hope to be able to give better answers when the police ask for help. To take part, head over to:

April 14 – Birds of Pray

Today’s factismal: The largest bird skull ever found was 28 inches long. Eighteen inches of that was the beak, which was used to club prey to death.

There is a joke in paleontological circles that tries to classify Big Bird. He isn’t a lark (despite what he said on Hollywood Squares) because he is too big. And he isn’t a parrot because the beak is the wrong shape to crack nuts. In fact, the group of birds that he most resembles is the Phorusrhacidae, the group whose name literally translates into “rag bearers” due to the wrinkly shape of their jaws. These flightless birds of prey ranged in size from 3 feet tall to more than nine feet tall (for reference, Big Bird is eight feet tall) and had long, sharp beaks that they used to club their prey before ripping it to shreds with their sharp talons and the tip of their beak. Like their very distant cousins the ostriches and emus, Phorusrhacidae could run quickly; unlike their cousins, the terror birds did it to catch their prey and not to escape being prey themselves. (Which brings us to the other paleontology joke about these critters: if one knocks on your door, you’d best start praying they aren’t preying!)

Not the sort of bird you'd want to meet in a dark alley (Image courtesy Michael B. H)

Not the sort of bird you’d want to meet in a dark alley
(Image courtesy Michael B. H)

The reign of the terror birds lasted for nearly sixty million years. They were an apex predator in South America from the time just after the death of the dinosaurs up until about two million years ago when South America joined up with North America. The new land bridge allowed predators from the North to head into terror bird territory; the increased competition combined with the climate changes caused by the drifting plates lead to the demise of this magnificent predator.

But many of their relatives and possible descendents still live today. And this weekend, you have a chance to see some of them and help science at the same time. That’s because this weekend is the Annual Midwest Crane Count. All you have to do to participate is go out and look for cranes; if you see any, report them to eBird (which will also help you identify any birds you do see). For more information, wing over to:

April 13 – Kilroy Was There

Today’s factismal: A wartime “casualty” is any soldier who is killed or wounded so badly that he can’t fight anymore.

Scientists are notorious for using words differently than other people do (“theory” anyone?) but they are hardly the only group to do so. For example, the word “casualty” means something different to a military strategist than it does to a civilian. Most non-military folks think of “casualties” as meaning that the soldier was killed but military strategists include people who are severely wounded as casualties. That’s because, like the killed, they are no longer able to fight and thus are no longer part of the battle. Perhaps no single event explains this better than the Battle of Somme. Over the course of a three-month long battle, more than one million soldiers became casualties. On the first day of fighting, some 70,000 soldiers were killed or severely wounded; fortunately, the original fierce fighting soon died back into slow, tedious, deadly trench warfare in which thousands of men would die to advance the line of battle by just a few feet.

Obviously, no soldier could stand that sort of toll for long. Instead of moving to the front and staying there, the soldiers were rotated in and out on a semi-regular schedule. If all went well (and it never did), a soldier would fight for four days at the front before falling back to provide support for four more days then wait a week “in reserve” and finally spend two weeks resting “behind the lines” before grouping at staging areas and  heading back to the front. Because a soldier was just as much a target behind the lines as he was on the front, the Allies frequently took advantage of France’s limestone-rich ground by moving the staging areas into the huge underground caverns surrounding the battlefields.

Turkish graffiti on the Acropolis (My camera)

Turkish graffiti on the Acropolis
(My camera)

Like all soldiers from the time of Troy to now, the soldiers in World War I spent their spare time behind the lines in the usual soldierly pursuits: swapping lies, reminiscing about home, and avoiding the NCOs. And, like all soldiers from the time of Troy to now, the soldiers committed a large amount of those pursuits to immortality via graffiti. With pencils, charcoal, and sharp sticks, they drew and carved memorials and pithy verses into the walls of the caves. If the graffiti had been exposed to the elements, then much of what had been done would have vanished. But the caves were sealed up following the war and are only now being reopened and explored, providing archeologists and historians with an amazing first-hand account of what life was like for a soldier during the War to End All Wars.

But the graffiti is only one source of information about the era. Another is the direct words of the soldiers as captured in their diaries. And that’s where you come in! Historians need your help in reading and tagging more than one and a half million pages taken from diaries kept by ordinary soldiers during World War I. You’ll be among the first to read about the heartbreak and heartbreaking courage that these gallant young men displayed. If you’d like to learn more about the project, then head over to: